A shuttle in a warehouse, such as a three-dimensional warehouse, travels along a runway to deliver articles to article spaces, such as shelves, or the like, extending along the runway and to retrieve articles from the shelves. The shuttle has an article-carrying area and may have a pair of arms to transfer articles between the article-carrying area and the article spaces. Some shuttles are capable of delivering and retrieving articles several articles deep on the article spaces. The arms extend outwardly from the shuttle in a cantilevered fashion quite far into the shelf area thereby experiencing forces tending to cause the arms to sag. This is challenging if it be desirable to handle articles of variable dimensions.